西南交通大学学报

Investigation Status and Development Trend of Hybrid Power Train Based on Fuel Cell

CHEN Weirong, QIAN Qingquan, LI Qi

2009, 22(1): 1-6.

[Abstract](1837)

Abstract:
As a novel train,a new rail transit tool with tremendous potential,with the features of high efficiency,environmental protection and energy saving,fuel cell hybrid power train(FCHP) will promote greatly the reform and development of rail transit systems.The investigation status and development trend of the FCHPT were introduced.Some key techniques,including the fuel cell system,hybrid power system,energy management control system,power storage equipment and high-pressure hydrogen safety measure,were analyzed and discussed.Furthermore,some important issues to need to be studied were pointed out.

Dynamic Interaction between Heavy Locomotive and Track under Longitudinal Force of Coupler

WANG Kaiyun, ZHAI Wanming

2009, 22(1): 7-12.

[Abstract](1683)

Abstract:
In order to investigate the wheel/rail dynamic performance of a heavy locomotive,the effect of longitudinal force of the coupler on locomotive-track coupled dynamics was taken into account.The dynamic performances under emergency braking on a tangent track and a curved track were computed numerically on the basis of the measured coupler force and irregularity.The research results show that all safety indices meet the limited values when a heavy locomotive runs on a tangent track at a braking speed of 80 km/h and on a curved track at a braking speed of 60 km/h.

State of Arts of Research on Railway Wheel Profile Optimization

LI Li, CUI Dabin, JIN Xuesong

2009, 22(1): 13-19.

[Abstract](2022)

Abstract:
The effect of railway wheel/rail profiles match on the dynamical behavior of railway vehicle/track and the wear and rolling contact fatigue of wheels/rails were described.The theories,techniques and results of railway wheel profile optimization were presented,their advantages and disadvantages were discussed,and their improvements were given.A feasible optimization method for railway wheel profiles was put forward.This method can consider multiple performance indexes,such as the contact stress,the wear index and the critical speed.In addition,the potential difficulty in mathematical modeling and the problem of low computing speed were pointed out,and their improved measures were given.

Optimal Design and Calibration Method of Six-Port System

XIONG Xiangzheng, LIAO Cheng, XIAO Huaqing

2009, 22(1): 20-25.

[Abstract](1641)

Abstract:
A microwave CMOS six-port system working in a frequency range of 1.7~2.3 GHz was designed.The correlation between voltage and power was determined with polynomial interpolation from power data.The reflecting coefficient of the system was tested with CMOS MIC(microwave integrated circuit)technique.The maximum difference among the measured ports was about 8 dB,the magnitudes of q points(q4,q5 and q6) were larger than 1,and the phase distribution at 2 GHz was the best,with phase differences of 97°,133°and 130°.No distinct changes in the system performances were observed with a 10% component tolerance.Compared with the results by a vector network analyzer,the biggest phase and magnitude errors in the operation band were 3°and 0.7 dB,respectively.

Web Document Ensemble Clustering Based on Adaptive Resonance Theory

YANG Yan, JIN Fan, KAMEL Mohamed

2009, 22(1): 26-31.

[Abstract](1579)

Abstract:
A method for Web document ensemble clustering based on adaptive resonance theory(ART) was proposed.It consists of two steps: clusters are obtained with an ant-based clustering algorithm,and the clustering results are combined as the final target by an ART neural network.Experiments show that the overall clustering performance is improved after combination.

Integrated Trust Evaluation Model in Grid Environment

ZHANG Nan, ZHANG Jianhua, HE Weilin, YAN Chunyan

2009, 22(1): 32-35.

[Abstract](1514)

Abstract:
To solve the security threaten due to in grid environment its instability and uncertainty,an integrated trust evaluation model was proposed to evaluate trust among grid nodes.In the model,a user describes trust with fuzzy logic,assigns weights to different attributes of a subject according to his concern degree,and considers historic communication record between him and concerned nodes as well as reputations of the nodes.Reputation of a node is dependent on a recommend coefficient that is determined according to the reliability of the recommender to avoid cheat from recommendation.An evaluation example was presented to show effectiveness of the model.

Adaptive Switching Interpolation Algorithm for Filtering Salt and Pepper Noises in Image

ZHOU Yan, TANG Quanhua, JIN Weidong

2009, 22(1): 36-40.

[Abstract](1643)

Abstract:
An adaptive switching interpolation filter was proposed using Newton interpolation method to remove salt and pepper noises in an image.Maximum-minimum noise detector and adaptive window size method were combined to identify pixels which are likely to be corrupted by noises.Then the image is restored by iterative interpolation to replace each noised pixel with a non-noised or repaired pixel in its vicinity.Simulation results on images with noise densities from 10% to 90% show that the proposed filter performs well in reducing salt and pepper noise in images with good detail-preservation.

Defect Extraction of ICT Images Based on Adaptive Morphological Filtering

FANG Liyong, LI Bailin, HE Chaoming

2009, 22(1): 41-44,65.

[Abstract](1682)

Abstract:
To overcome the shortcomings of the current defect extraction methods for ICT(industrial computerized tomography) images,an adaptive filtering method based on the mathematical morphology was proposed.Firstly,with this method,the primary region of a structural element is automatically chosen in the light of region size after the watershed transformation of full ICT images.Secondly,the ellipse fitting operation is applied to the boundary of the primary region to get the final structural element.Then the background images are gotten by the closing operation of the mathematical morphology on the original images using the final structural element.Finally,the defect images are obtained by subtracting the original image from the background images.The experimental results show that compared with the current methods,the proposed method can obtain a good result of defect extraction of ICT images.

Fast Algorithm for Real Signal Sparse Decomposition Based on FHT

LIU Hao, PAN Wei

2009, 22(1): 45-48.

[Abstract](1391)

Abstract:
A new signal sparse decomposition approach was proposed for easy software implementation.This algorithm converts very time-consuming inner-products in sparse decomposition into cross-correlations,so that the speed of sparse decomposition is increased greatly.For real signals,cross-correlations are done by fast Hartley transform(FHT).Simulation results verified the effectiveness of the proposed algorithm.

EMD for Multi-component LFM Radar Emitter Signals

YU Zhibin, JIN Weidong

2009, 22(1): 49-54.

[Abstract](1574)

Abstract:
A method for detection of multi-component LFM radar emitter signals was proposed based on empirical model decomposition(EMD).In this method,to improve decomposition precision,a forecast method of radial basis function(RBF) network is used to suppress the end effect of EMD,the correlation coefficient and auto-correlation function are used to estimate the component number of radar signals,and an EMD filter and mean value glide are used to eliminate the effects of noises.Theoretical analysis and experimental results show that this method can accurately Abstract instantaneous frequency of every component of LFM radar signals and estimate their component number.

Single Frequency Estimator Based on Prefilter

GAN Lu, WEI Ping, XIAO Yangcan

2009, 22(1): 55-59.

[Abstract](1557)

Abstract:
A new method for estimating the frequency of a complex sinusoid in complex white Gaussian noise was proposed to acquire a uniform performance within whole frequency estimation range.With this method,the signal-to-noise ratio(SNR) of input signal can be improved by utilizing a non-rectangle prefilter.Furthermore,compared with some conventional autocorrelation-based and phase-based methods,the new method can attain the Cramér-Rao bound(CRB) even at a low SNR value by using the iterative method.A theoretic analysis and numerical simulation show that the performance of the proposed method is uniform and good within the frequency estimation range.

Damage Detection of Bridge Structures Based on Moving Vehicle Caused Vibration

SHAN Deshan, LI Qiao

2009, 22(1): 60-65.

[Abstract](2629)

Abstract:
Based on the vibration caused by moving vehicles,the pattern recognition method was adopted to identify the damage detection,localization and severity estimation for bridge structures.With the technique,the dynamic responses of a bridge under the same moving vehicle for various predefined damage locations and severities are figured out,and the responses at testing points are written down to form a damage pattern database.Then the measured responses under moving vehicles,collected from the instrumented sensors on a bridge structure,are compared with the damage patterns,and the nearest method for clustering analysis is engaged to carry out the damage detection,localization and severity estimation.The comparison is displayed in a contour or image plot with damage location and severity as independent coordinates.By taking the damage detection of a simply supported beam under a constant moving load with a constant speed across the structure as an example,the concept,effectiveness and robustness of the pattern recognition were demonstrated numerically.The numerical results show that the proposed technique is effective and robust to estimate the damage location and severity of bridge structures.

Coupling Vibration Simulation of Long-Span Continuous Beam Bridge on Passenger Dedicated Railway

CUI Shengai, ZHU Bing

2009, 22(1): 66-71.

[Abstract](1927)

Abstract:
Based on the multibody system dynamics and the finite element method,a new co-simulation method for the coupling vibration of a vehicle-bridge system was proposed.By using the finite element substructure method,a dynamic analysis model for a long-span continuous beam bridge,Bahe super-long bridge on Zhengzhou-Xi’an passenger dedicated railway,was established,and the natural vibration properties of this bridge were analyzed.A whole vehicle model was set up with the multibody system dynamics.Then the co-simulation of two subsystems(vehicle and bridge) was performed by interfacing data exchange at discrete communication points,and the coupling vibration simulation was achieved.The research results show that the co-simulation is feasible and its realization provides a new strategy for the research on the coupling vibration.

Advantage Analysis of Risk Model Based on Analytic Hierarchy Process

JIA Hong, ZHOU Bo, LIU Guangbing

2009, 22(1): 72-76.

[Abstract](1598)

Abstract:
Based on the situation that construction supervision and project management are two parallel operations in Chinese construction industry,the analytic hierarchy process(AHP) was adopted,and a risk analysis model for the implementary stage of construction projects was established to show an optimal management mode.Through fuzzy judgment,complex risk points were obtained respectively for the separate and combined applications of construction supervision and project management,and an optimal management mode was decided based on the points.The result shows that construction supervision combining with project management is the optimal management mode in the present status.

Time Series Extracting of Ground Deformation by Short Spatio-Temporal Baseline PS-DInSAR

MA Deying, LIU Guoxiang, CAI Guolin, DING Qiong

2009, 22(1): 77-82,111.

[Abstract](1630)

Abstract:
In order to decrease the negative effects of spatio-temporal decorrelation in differential synthetic aperture radar interferometry(DInSAR),a method for analyzing the time series of ground deformation with a network formed by connecting adjacent permanent scatters(PSs) was proposed.With this method,interferometric combination is formed by considering both temporal-and spatial-baseline threshold,linear and non-linear motions can be extracted and separated from the PS-networking model,and the entire time series of ground deformation can be reconstructed by the singular value decomposition.An experiment was performed using 39 ERS-1/2 C-band SAR images,acquired from 1992 to 2000,related to the Phoenix region of the United States.The experimental results show that the proposed method is feasible and effective.

Building Extraction from LIDAR Data Based on Shape Analysis of Contours

REN Zizhen, CEN Minyi, ZHANG Tonggang, ZHOU Guoqing

2009, 22(1): 83-88.

[Abstract](1629)

Abstract:
A new method for building extraction,without the need for DTM(digital terrain model) advance extraction,was proposed based on LIDAR(light detection and ranging) data and the shape analysis of contours.In this algorithm,firstly,the initial segmentation of DSM(digital surface model) contours is carried out based on the closure of a contour and the area enclosed by the contour,and the initial contours of buildings are acquired.These buildings are consisted of closed contours expressing building points and vegetable points and have a certain area.Secondly,after smoothing those initial contours,they are segmented to building contours and non-building contours based on dimension surveying and shape characteristics of the contours,such as rectangle tolerance and circle tolerance.Finally,the building contours predigested by the topological relation are served as the outlines of buildings and normalized based on the vertical or parallel characteristics of building outlines.In a test on an undulated region,buildings’ contours were extracted from DSM contours and regularized.To validate the test results,an overlay of extracted buildings’ outlines and an aerial image was checked.The result shows that the proposed method has an accuracy up to 80% and can effectively extract big and independent buildings in undulated regions.

Proposing-Testing Generic Reasoning and Its Application in Railway Location

HAN Chunhua, YI Sirong

2009, 22(1): 89-95.

[Abstract](1603)

Abstract:
To develop an inference engine that can be reused in an intelligent railway location system and directly utilize factual knowledge in software engineering,a proposing-testing generic inference model was put forward.In this model,knowledge is represented using the object-oriented technology.By using a hierarchical model,rules are described as factual knowledge,constraint knowledge,heuristic knowledge,tactful knowledge and goal verifying knowledge.knowledge’s executable form is related to its readable form by using a bi-formal model.Problem-solving method is described as inferential control knowledge,and task verifying knowledge is used to describe task goal.So reasoning control strategy can be separated from an inference engine.The inference engine takes data-driven as its control strategy.Dynamic pattern matching and rule executing are fulfilled using the reflection technology.By classifying knowledge based on knowledge categories and knowledge domain characteristics,conflict resolution mechanism is constructed.Therefore,the reasoning process is controllable.This method has been successfully used in railway location to automatically generate new railway horizontal alignment.

Numerical Analysis of Aerodynamics of High-Speed Trains Running into Tunnels

ZHAO Jing, LI Renxian

2009, 22(1): 96-100.

[Abstract](2062)

Abstract:
To get the approaches to decrease the aerodynamic effects,the aerodynamic effects of high-speed trains running into tunnels were investigated by means of the computational fluid dynamics method with the technology of moving grids based on the 3D Reynolds average Navier-Storkes equations of viscous compressible fluid and the two-equation turbulent model.Thirty flow field situations,including 2 types of trains(ICE and Series 300 Slinkiness),5 running speeds(200,250,300,350 and 400 km/h) of trains and 5 sizes of tunnel section,were simulated numerically.The change tendencies of the aerodynamic drag of trains and the aerodynamic pressures on tunnel wall and train head were obtained.The influences of running speed,blocking ratio,train head shape and line condition on the aerodynamic effects were analyzed.The research result shows that the influences of the running speed and the block ratio on the aerodynamic effects have a certain regularity.

Perturbed Numerical Algorithm of Nonprobabilistic Convex Set Theoretical Models for Temperature Field

LI Jinping, CHEN Jianjun, ZHOU Chuanjun

2009, 22(1): 101-105.

[Abstract](1596)

Abstract:
In order to investigate the uncertainties of heat conduction,the uncertainties of physical parameters and initial and boundary conditions of structural temperature fields were described using convex models.The perturbation formulas of the upper and lower bounds of responses of temperature fields with unknown-but-bounded parameters were derived via the combination of the matrix perturbation theory and the convex models.A comparison between the results obtained respectively by the convex models and the interval analysis method was made by a numerical example.The results show that the width of the upper and lower bounds of temperature field responses calculated by the convex models is greater than that calculated by the interval analysis method.

Design of Electrical Control System of Test Machine of Automobile Clutch Centre Plate

ZHANG Bangcheng, LU Hongwei, WANG Zhanli, ZHOU Zhijie

2009, 22(1): 106-111.

[Abstract](1593)

Abstract:
Through the analyses of the algorithm of sliding mode control and the Kalman filter,a compound sliding mode control algorithm was proposed on the basis of the Kalman filter.In order to improve the controller performance of the test machine of automobile clutch centre plate,the proposed algorithm was applied to its electrical control system.The simulation shows that compared with the compound PID(proportion integral differential),this algorithm has high steady accuracy,tracking accuracy and a fast response speed,and the controller with the Kalman filter can eliminate the random noise and the industrial frequency disturbance.The measurement result shows that the testing precisions of displacement and torque for the test machine are ±0.005 mm and ±0.05 N·m,respectively.

Bi-level Programming for Optimization of Contraflow Lanes after Massive Activities

YAN Xinping, LÜ, Nengchao, LIU Zhenglin, XU Kun

2009, 22(1): 112-117.

[Abstract](1968)

Abstract:
A bi-level programming optimization model was proposed to configure contraflow lanes around the site after a massive activity for quick evacuation.In the proposed model,both the decision by traffic authorities and the reaction by the traffic participants were considered.The upper model is to minimize the total evacuation time,and the lower one is an equilibrium model determined by every traffic participant.A discrete particle swarm optimization algorithm was used to solve the bi-level programming problem.The proposed optimization method was verified by a simplified actual traffic network.The simulation results indicate that the optimal contraflow lane setting based on the proposed model reduces the total evacuation time by at least 20%.

Maximum Flow Assignment Algorithm for Transshipment Nodes with Flow Demands in Transportation Network

KOU Weihua, LI Zongping

2009, 22(1): 118-121.

[Abstract](1684)

Abstract:
In transportation networks,a transshipment node with flow demands fails to conform to flow conservation,and can not be categorized to a source,a sink or an intermediate node.To solve the maximum flow problems of transportation network containing this kind of transshipment nodes,the node is split into a sink node and an intermediate node.Following the principle in Ford-Fulkerson algorithm to search augmenting paths,a maximum flow assignment algorithm was proposed for transportation networks containing transshipment nodes with demands.The proposed algorithm consists of a method to search augmenting paths on the transshipment nodes,a formula to calculate adjustment quantities,and a method to change flows.

Multi-period Programming Approach for Optimal Design of Manufacturing/Remanufacturing Logistics Network

DI Weimin, MA Zujun, HU Pei

2009, 22(1): 122-127.

[Abstract](1825)

Abstract:
A mixed integer non-linear programming model was proposed for optimal design of manufacturing/remanufacturing(M/R) logistics network to determine the site and number of the facilities in different periods.In the model,multiple periods,capacities of facilities and time value of capital are taken into account,and forward/reverse logistics is integrated.The objective of the model is to minimize the total cost of the M/R logistics network in all the periods.A hybrid genetic algorithm for solution of the proposed model was presented.A numerical example verifies the validity of the model and the algorithm.

Collaborative Optimization of Capacity Utilization and Flow Assignment in Airport Terminal Area

ZHANG Honghai, HU Minghua, CHEN Shilin

2009, 22(1): 128-134.

[Abstract](2439)

Abstract:
To make full use of airport terminal area capability and reduce flight delay,capacity utilization and flow assignment were optimized collaboratively.A model for collaborative optimization of capacity utilization and flow assignment was proposed.In the model,arrival and departure are considered to be two interdependent processes,the capacity in the airport terminal area is taken as the constraint,and the objective is to minimize the total delay of all arrival and departure flights.The model contains a delay cost priority coefficient to describe the preferences of airlines.A genetic algorithm was designed to solve the proposed model.A simulation example shows that the proposed model can optimize the capacity utilization and flow assignment synchronously,with the preferences of airlines being considered,and the genetic algorithm works well.

Simulation Analysis of Passenger Departure Procedure in Airport Terminals

LU Xun, TANG Xiaowei, ZHU Jinfu

2009, 22(1): 135-140.

[Abstract](1746)

Abstract:
To study passenger departure processes in airport terminals,improve their operation efficiencies,reduce delay,and improve service quality,a simulation system was developed using ServiceModel software and based on a survey on passenger departure processes and analysis on their behaviors in Shanghai Hongqiao International Airport(SHIA).Simulation on flight data of a typical day in SHIA revealed that the passenger security check was a bottle-neck of the departure procedure.Suggestions to remove the bottle-neck were proposed,and the efficiency of passenger security check was increased by 42% after optimization.

Interpretation of Traffic Flow Breakdown with Density-Flow Model

WANG Xin, WANG Wei, LI Wenquan, CHENG Lin

2009, 22(1): 141-146.

[Abstract](1692)

Abstract:
To interpret the phenomena of traffic flow breakdown,common parameters of driving behaviors,such as headways and drivers’ reaction time,etc.,were analyzed.Models were derived to describe the relationships between flow and wave speed,speed and density,and density and flow.The curves for the relationships were obtained under different reaction time of different drivers during acceleration or deceleration.The simulated results indicate that the maximum wave speed decreases and the peak flow value increases with a decrease in reaction time of drivers,and that the change in reaction time is the essential cause of traffic flow breakdown.

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2009 Vol. 22, No. 1